Kcaptcha session vars not being set

[eluser]bmgz[/eluser]
although I have clearly stated that it must be set:

Code:

function captcha(){
    $this->load->library(array('session', 'kcaptcha/kcaptcha'));
    $this->session->set_userdata('captcha_keystring', $this->kcaptcha->getKeyString()); // LOOK HERE???
}

I think there is a bug or something, as far as i can make out, when I include a library, CI automatically creates an instance of it? in this case the Kcaptcha class automatically spits out a JPEG with an image header etc.. I don't see how that would interrupt the flow on the php script on the server-side, the line after load->library should still be called, so something is wrong with the last line of code above..???